ESP32 - Rain Sensor - LED

We are going to learn how to program ESP32 to turn on the LED if the rain is detected.

Hardware Used In This Tutorial

1	×	ESP-WROOM-32 Dev Module
1	×	USB Cable Type-C
1	×	Rain Sensor
1	×	LED
1	×	220 ohm resistor
1	×	Breadboard
1	×	Jumper Wires
1	×	(Recommended) ESP32 Screw Terminal Adapter

Or you can buy the following sensor kits:

1	×	DIYables Sensor Kit (30 sensors/displays)
1	×	DIYables Sensor Kit (18 sensors/displays)

Disclosure: some of these links are affiliate links. We may earn a commission on your purchase at no extra cost to you. We appreciate it.

Introduction to LED and Rain Sensor

Unfamiliar with led and rain sensor, including their pinouts, functionality, and programming? Explore comprehensive tutorials on these topics below:

Wiring Diagram

This image is created using Fritzing. Click to enlarge image

If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: How to Power ESP32.

ESP32 Code

/* * This ESP32 code is created by esp32io.com * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-rain-sensor-led */ #define RAIN_SENSOR_PIN 25 // The ESP32 pin GPIO25 connected to the sound sensor #define LED_PIN 26 // The ESP32 pin GPIO26 connected to the relay int rain_state = LOW; // current state of rain sensor's pin int prev_rain_state = LOW; // previous state of rain sensor's pin void setup() { Serial.begin(9600); // initialize serial pinMode(RAIN_SENSOR_PIN, INPUT); // set ESP32 pin to input mode pinMode(LED_PIN, OUTPUT); // set ESP32 pin to output mode } void loop() { prev_rain_state = rain_state; // store old state rain_state = digitalRead(RAIN_SENSOR_PIN); // read new state if (prev_rain_state == LOW && rain_state == HIGH) { // pin state change: LOW -> HIGH Serial.println("Rain detected!"); digitalWrite(LED_PIN, HIGH); // turn on } else if (prev_rain_state == HIGH && rain_state == LOW) { // pin state change: HIGH -> LOW Serial.println("Rain stopped!"); digitalWrite(LED_PIN, LOW); // turn off } }

Quick Instructions

If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
Do the wiring as above image.
Connect the ESP32 board to your PC via a micro USB cable
Open Arduino IDE on your PC.
Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
Connect ESP32 to PC via USB cable
Open Arduino IDE, select the right board and port
Copy the above code and open with Arduino IDE
Click Upload button on Arduino IDE to upload code to ESP32

Move your hand in front of sensor
See the change of LED's state

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

Making video is a time-consuming work. If the video tutorial is necessary for your learning, please let us know by subscribing to our YouTube channel , If the demand for video is high, we will make the video tutorial.

Learn More

※ OUR MESSAGES

As freelancers, We are AVAILABLE for HIRE. See how to outsource your project to us
If this tutorial is useful for you, please support us to make more tutorials.
Please feel free to share the link of this tutorial. However, Please do not use our content on any other websites. We invested a lot of effort and time to create the content, please respect our work!